Nutrient-Sensitive Epigenetic Modifiers as Candidate Biomarkers of Metabolic Dysfunction in Obesity: A Nutrigenomic Review.

Obesity is a complex metabolic disorder resulting from interactions among genetic, environmental, and dietary factors. Traditional clinical markers may provide limited insight into the biochemical mechanisms that link nutrition and metabolic dysfunction; in this context, the epigenetic mechanisms through which nutrients modulate gene expression are central to understanding metabolic homeostasis. This review summarizes the published evidence on nutrient-driven epigenetic processes in obesity, focusing on DNA methyl donors, such as folate, vitamin B12, choline, betaine, serine, and methionine, and their effects on methylation and DNA methyltransferase activity. Metabolites such as acetyl-CoA, NAD+, and short-chain fatty acids (SCFAs) can also influence histone modifications, while diet-responsive microRNAs can regulate networks involved in adipogenesis, lipid metabolism, inflammation, and insulin signaling. Recent studies have identified epigenetic signatures associated with adiposity and metabolic traits, many of which are linked to the risk of cardiometabolic disease. This review is structured around the concept that nutrient-sensitive epigenetic mechanisms act as candidate biomarkers, linking dietary exposure to metabolic dysfunction. Recent evidence supports the idea that nutrient-epigenetic variation could complement traditional metabolic evaluations by offering mechanistic insight and translational direction. These findings suggest that nutrient-sensitive epigenetic mechanisms are biologically plausible candidate biomarker layers; however, their clinical implementation is currently limited by issues including tissue specificity, reproducibility, and the need for prospective validation.